Dodge Durango Forum II Archive

spark plug question

I went to get new plugs the other day and the guy handed me 5224 autolites. I asked about the 3923 and he said that the 5224 was what the computer showed was the right plug. I asked him what the difference was and he didn't know. When he looked it up in his book he then told me the right plugs are the 3924. So I told him to give me the 3923 instead off the recommendation of everyone on the forum. What I would like to know is whats the difference and why the computer shows 5224 and the book said 3924? I have a 5.9

Fri Jun 29